Is? No. Can? Yes (wired). Will? Doubtful. Unlike the vast majority of USB controllers, the Xbox 360 controller uses the Microsoft-proprietary XInput standard rather than the open HID standard. Adding support for a single controller would be low on the priority queue when tons of controllers are already covered under the HID standard. The only thing I'd see anyone bothering to implement specifically for one controller would be the Wii U's Gamecube Controller adapter if it happens to not follow the HID standard.This has been asked some times with different answers, but as it was some time since i last checked i guess there is a chance something has happened.
Is/Can Xbox 360 Controller be supported?
Either Wireless or Wired (my guess is Wired is a lot simpler).
Thanks